Update app.py

app.py

@@ -98,7 +98,7 @@ def invoke(openai_api_key, rag, prompt):
             #                                  persist_directory = CHROMA_DIR)
             # Document retrieval
             result = document_retrieval_chroma(llm, prompt)
-        else if (rag == "MongoDB"):
+        elif (rag == "MongoDB"):
             # Document retrieval
             result = document_retrieval_mongodb(llm, prompt)
         else: